At the moment all golang.org/x/* sub-repositories are built/tested on a limited set of builders. For golang.org/x/sys it would be nice to enable builders for dragonfly/amd64 and solaris/amd64 at least (and maybe freebsd/arm and netbsd/arm) to increase test coverage. For now I run semi-regular build/tests of x/sys on these via gomote or on my local VMs/machines, but it would be nice to have it automated.
@bradfitz Primarily, I mean post-submit builder. But pre-submit would of course also be nice, if it's possible to have them only for x/sys. I guess it doesn't make sense for most of the other x/* repos.